And he says he isn't surprised by the goalscoring success Gundogan has enjoyed this season.
Oenning told Goal: "In my opinion, Ilkay has always been a number 10, a player who should be in and around the box and score goals.
"The way he plays in Manchester City now."
He added: "Klopp and I disagreed about Gündogan's best position. We often argued about it and I thought it was wrong of Klopp to play him as a defensive midfielder."